Dry cell with improved thermoplastic seal



p 23, 1952 A. w. SIMPSON DRY CELL WITH IMPROVED THERMOPLASTIC SEAL FiledSept. 15, 1948 IIYVENTOR. y tifiarld pimp 101v Patented Sept. 23, 1952TH IMP ROSZED' .YP'IQKSTIC'SZSEAL -$Arthur vv. {simpsbn,Fresnel-it,hlutsassignorphy 2? mesne ssig'fl-meflts, to Burgess BatteryCompans;.Freeport.illl.,;a. corporation-1M1DelawareJT'ADpIicationSeptember 1siisisiserial-iqo; 4,9;322

This invention relates co-electricidry' cellsf'and more, particularlyto'impr'ove'wmeans" or se'aijing "the tops of cylindrical" type, zsifch asffia'shlight,

cells.

' The: principal obj eat" of the invention *isfiq im vprove the sealingstructure" of cylindrical cells of "the'type whichdepend upon athermoplastic sealing materialfor hermetically closing the tops of .thecells. This is accomplished rmeipany'p'y reti'ucingithe'span; of'thefsealfincreaisiifg' the ra'itio of .depth" to span thereof;andproyidingfsuifaces "to which the sealing""material'*will-1"tena'eiously adhere. Increased" s'tren gthalsof resultsfironithereinforcing effect of'indentd and embfdded 'sim- .por-ti'n'g -surfaces.

A"further objectisto provide a'simple andc'omf'pactftop' assembly" fora1drycelbwherein'asingle washer supports'the molten sealingmaterialdur-"in'gthe sealing procedureand' definesan-air'space surrounding. thevseal, in addition toyits" ordinary function of centeringthe carbonelectrodes and "confining the cell mix.

' In' the accompa ngidrawing, 7

Fig. l'is aside View,partlyin=section,'-oi*a"dell "embodying atsimpleiform of" theinventionfiand Figs. 21 to? '4: are "fragmentaryside'viewsipartiy section, illustrating i'eertain'rmodlfications oftheinvention. V

f'Essentially, the invention "contemplates" ac'ell formedinwardly 'and'turned'dQWn' tofth'e' washer to forma well forthereception fsealingimajtetrial adjacent the*carb'omelectrode ami aneiipa-n-"sion'spacesurrounding thewelland-adjacentthe can. Thus, the space"abovethe" -washer"is divided by j a circular partition concentric withthe'carbon and camelectrodes into an air space am a sealing "space, thelatter being'considerablysmaller than-"known construction-bl this typecell.

In' oneformof'modernrdry cell, theisepar'ating layer lying between'thef"mix"';an'd thec'arrelectrode "is a starchy compositionapplled -a-entrifugal operation which'spreads*the' "material": in 'fauniform'layer "and carries the"separating layer t the top: edge: of the can,This "starchy; "layer does "not "have. suflicient mechanical strenkth tosupportand hold a" thermoplastic se'al formedin' "'the top' of "thecellin the ordinaryfmanner. Spe- "zeialprovisionmust bemaide' for the?sealing? of isuch cells. "Furthermore; the" starchylayefmust -itself be'completelyfenclosed'by tire -seal. Be-

causethej present. invention is particularly useful inthesealingof suchcells for the principal reason that it presentsa metallic surface to thesealing material for good'aclhesion'and support,

" pon coni'pletion of the -can forming operation,

iithe' invention=is' iillustransed as embodied: iniz-su'chae cell.

' llie 'cell illustratekl imEig. 1': incorporates: .the

usual elementsLincludinga metalliclcan. hot-zinc,

* 'magnesium, or other-suitablerm'etalaa. cylindrical5-in'si'1latin'gfiackt 2 fsurroundlngritheecanrrand: a

of x:surroundingaaycentralicarborr teran separated from can:lubyasstarehy rasseap;lizisepressedaupenith iiipper ende'arbomterminalz-kamt;aawashert"I suitsable.snon conductingimaterial,:isuchsa impre nated eafiiboard; isiimpaledxuponvcarho ;4.;: and restsupon the mix body. A seal 8..cnmpletes;and closes the cell.

15 producingeaeelluin. accordancestwithithe indownsias:andiorstheipurposes herein .described..

-Thessepar a'tings layer;- isifirst: applied to: .the..:in-

terior; surfaces= of the'- cell. -The mix canbomtermmalr and washer arethenrinsertecli andzrthereen "iSlGQIdY-YOF'HIE sealing operation,"lTosprcvidezthe top closure and seal the portion:.ofi theimetalcanextending above the c'ellis iforme'd: inwardly 15 and then turneddown as shown:in"Fig;1. =In12hiS particularform- 'of the:inventiomstheulength 1. of 'the can- Bastien that it giust reachesithe;washer when -the' forming opera-tion, describedpsisilcom- .pleted. Inthisway, a well is -provided-i between *the n'etr'overted en'd portionofitheican,s-partition -'t'n -"and theeentral terminal of theeens-washer 1 forming the floor of the well. p in sd--forming '=the-cell;' it is desirable to carry the partitioni 9='-as far initoward Ythe'centerielectro'cle as' possible to provide an expansiomspace -'l 0'-ef-maximum volume-and zreducel-the .spank of seal 8 to a minimum. Themetallic lean-mush: of ycoursewheelectrically --insulated :from terminal4 and-' ca'p 'i to 'avoidthe: short circulating -,of -..the

'*'*niol-tense'alin'g* material is poured into ithe well-surrounding-'-central terminal-4 to: iorm-seal1- 8. Thissealadheres-strongly tothe can and central 5- terininal--surfaces anditothesurface Iof' washer 1 :1:and will withstand'thesubstantialpressuresilthat may 'be"bl li1t-{l1p" within thei-cell" bythe evolution *of'jgases; Any tendency oi mix body' 3. toza swellpresses-upwardly upon washer 1,=but this load is "nofi borne byf theseal alone since theedgeofithe "'"canenga-ges-the' washer and the metalstructure ,-will -=oppose*-such-upward movement. -Any. yielding will 'belikely to belimitd -to theperipheral portion ,ofwthe 'washer into-'-expansion jspace l0 arid the'seaiwillremain-intact.

."Inithe'cell illustratedin Figz 2f= the end portion of metallic can Iis continued inwardly at l I from partition 9 and a shallow up-turnedflange I2 is formed by the portion adjacent the edge of the can. Whenseal 8 is poured, flange I2 is embedded within the seal and serve tostrengthen the sealagainst-radially-directed;forces.

Tl'ieis'tructure of. Fig. 8 is" similar to that of Fig. 1 except that anadditional crimp I3 is formed in the portion of the can which forms ipartition 9. This crimp extends inwardly toward the center of the celland is embedded injsea l" forming a tongue and groove engagement whichopp sing; upward pres ing,.-ra dially .from said central terminal towardstrengthens the seal in sures within the cell.

The cell of Fig. 4 is also' similar to-that of Fig; 1' except that theportion of the can which forms partition 9 is curved convex inwardly; Inthis structure the seal is rigidly secured inposition by reason of itsgrippi g configuration as well as the adhesion of. thesealing materialto the engaging surfaces. .51:

Since. the span .of any form of seal described is substantially lessthanithatof thek lDWn-full parting from the essentialinventiveconcepthereindisclosed, Also, non-conductive cementsor,settingmastics of .various kinds may bens ed as the full :equivalentiof,the thermoplastic sealing material. I

Invention is claimed as follows? 1.: l. Ina dry cell, an integralimetalcan having a top portion and abody-portion; a central ter- 'minal withinsaid can and exposed :atthetop of the-cell, a flat washer-ofnon-.conducting-mate- :rial spaced from the topof the cell;andextendingv --'.radially from .said central terminal toward said 1.oan,i-said top portion of,saidcan extendinginwardly at thev top of the.cell to a; location intermediate saidcentral terminal and, said bodyper- 1 in the down-turnedportion 'tion of saidcan andthence, extendingdownwardilyrto said washer,and;a.;bodyof; sealing mate-' ..rial uponsaid washeriand confined between said :centralterminal and thedown-turned portion of said top. portion oflsaid caninsealingengagementtherewith.

2. Structure in accordance with claim litwliere concave inwardly; s i in3. Structure in accordance with claiml wherein; the down+turned portionof the can is crimped :vto form atongue whichisembedded within a,

. s corresponding groove .in the. periphery of ;the body of sealingm-a-teria-l.

- 14; In a drys cell, ,anintegiilimetal can havin a top portion'andahodyportion, a central terminal within said can and exposed at the top of ihercell, .a..washer of non-conducting. material a shallow washerbetween. "said centrahtermi al andlthe down-turned portion-of,,said;can' and; o ring said in-turned portion and sad flange A rycell. .cqmpris nsasr n o th can i W 'Y onfsaid 4 cell, a flat washerextending between said can and terminal and spaced from the top of thecell, the top portion of said can being inwardly retroverted to definewith said washer an annu- 5 l'ar expansion chamber, and sealing materialon saidmasher between ,the ,retro,verted top portion ffjof said can andsaid rod terminal in sealing engagement therewith.

6. In a dry cell, an integral metal can having atop portion and a bodyportion, a central terminal within said can and exposed at the top ofthecell, a flat washer of non-conducting materialspaced from the top ofthe cell and extendls said can, said top portion of said can extending Iinwardly atthe top of the cell to a location intermediate said centralterminal and said body portion ofsaid can and thence extendingdownwardly to said washer to ;form an expansion cham- -ber between saidtop portion of said can and saidwasher, and a body of sealing materialupon s aid; w-asher betweenjsaid central terminal and the down-turnedportion of said top portion of I said can,. the depth ,of said body ofsealing'material heing approximately equal to the length of aiddown-turned portion of said top portion of saidcan.

7. A dry cell comprising a cylindrical can, a

central rod terminal exposed'at the top of the cell. abody offmix'surroundingfsaid central rod terminal, .e. flat washer resting uponsaid body of mix and'ext'ending between said "can and terminal andspacedirom the top'of the cell, the top. portion of said can beinginwardly retroverte-d todeflne with said washer an annular'expansionchamber, and sealing material on said' Washerbetween theretrovertedtopportion of said" can and. said rod-- ternii'nalfinsealing. engagement 40 l 8. Ina dry cell, acylindrical-fmetal can,'a'central terminal within said canand exposedat the top of the cell, aflatwashe'r'of non-conducting material spaced Tfroinfthe top of l the'cell and extending radially from said central terminal towardsaidan','e1e'y1inanea1 partition arranged it upon saidwashei' coaxially withsaid can and intermediate said central terminal andsaid'can, an

annular closureextending over the-space. above said washer and betweensaid can'an dsaid partl- 5Qi to .iorm an expansion chamber; and a body goi. sealing material substantiallylfillingand conj fim'ed' to the spaceaboye saidw'asher and between said partition anidis'a'id" centralterminal 'in's'eal- ;in eiiggeinenttherewith;

l, 9 in a dry cell',-Ian'integral'metal can having atopportion'aridabody portion, a'central terminal within saidlcan'andexposed. attthe top of the cell, ail-atwasher of non-conducting materialspaced from the top of the cell and extending radially from said centralterminal toward said can, said .top portion oftsaid 'can extendinginwardly' -at'the top of the'cell toa loca- 1 tionv intermediatefsaidcentral terminal and said L body s anner/sai can'andthence' extending C5downwardly to said washer, and a body of sealing material uponsaidfivashe'r and confined between Li said centraltermin'al [and thetownturnedfpor- .tion of s'aidlto portion (or ear-steamseaimsen- 1 eas mnt therewithIsafd'inwardlyefiendingpor- 79 .tion of. thetop'ldi the .canseine exposed to the a annular siirtacejs'urroiinding said bodyo'flsealing material. 'Q' SIMPSON.

5 3 V 6 REFERENCES-CITED Number Name Date The following references areof record in the 2,060,799 f 17, 1936 fil f this patent; 2,079,495Derbel May 4, 19 7 2,179,816 Drummond Nov. 14, 1939 UNITED STATESPATENTS 5 2,399,089 Anthony Apr. 23, 1946 Number Name Date 2,463,454Birdsall Mar. 1, 1949 454,598 Hathaway June 23, 1891 2,490,598 OliverDec. 6, 1949 1,203,279 Tarver Oct. 31, 1916 1,487,728 De Olaneta. Mar.25, 1924 FOREIGN PATENTS 1,794,770 Andre June 17, 1930 10 Number CountryDate 3 ,015 Deibel Jul 5 932 173,515 Great Britain Aug; 31, 1922

